Fast processing of information represented in digital holograms is provided to facilitate converting a complex Fresnel hologram into a phase-only hologram, which can be a localized error diffusion and redistribution (LERDR) hologram, for displaying 3-D holographic images representative of a 3-D object scene. For a complex Fresnel hologram representing a 3-D object scene, a holographic generator component (HGC) can directly apply an LERDR process to the complex hologram to facilitate converting the complex hologram into an LERDR hologram. As part of the LERDR process, the HGC can partition the complex hologram into segments, convert the complex values of the pixels in each segment to phase-only values, and apply error diffusion to each segment to facilitate generating the phase-only hologram. The HGC can apply error redistribution to the last pixel of each segment to produce the resulting LERDR hologram, which can be displayed on a phase-only display device.

A light-emitting device including at least a metal layer able to be heated and to propagate surface waves consecutive to the heating of the metal layer, with the metal layer being structured such that it comprises several diffraction patterns able to carry out a diffraction of the surface waves to free-space propagation modes, wherein a synthetic hologram is encoded such that a phase image of a pixel of the hologram is encoded by an offset in the position of one of the diffraction patterns, and a heater of the metal layer.

There is provided a spatial light modulator arranged to display a light modulation pattern including a hologram. The spatial light modulator includes a liquid crystal on silicon spatial light modulator having a plurality of pixels. The hologram has a plurality of pixels. The spatial light modulator includes a silicon backplane. Each pixel of the spatial light modulator includes a light-modulating element and a respective pixel circuit. Each pixel circuit is embedded in the silicon backplane. Each pixel circuit is arranged to drive the corresponding light-modulating element. Each pixel circuit is further arranged to combine a received pixel value of the hologram with a corresponding pixel value of the light processing function such that the light modulation pattern further includes the light processing function. The light processing function includes a lens function and/or a grating function.

A phase distribution is calculated such that modulated light has a predetermined intensity distribution on a target plane and displayed on a phase modulation plane, readout light enters the phase modulation plane so as to generate the modulated light. When calculating the phase distribution, a region on the phase modulation plane is divided into N regions A.sub.1 . . . A.sub.N, with sizes set such that integration values of an intensity distribution in the regions are equal to each other. Further, a region on the target plane is divided into N regions B.sub.1 . . . B.sub.N, with sizes set such that integration values of an intensity distribution in the regions are equal to each other. The phase distribution is calculated by obtaining an optical path length from the region A.sub.n to the region B.sub.n, and determining the phase of the region A.sub.n based on the optical path length.

Disclosed is a method and a device for coding a sequence including first and second digital holograms representing respective scenes, the digital holograms being represented by a set of wavelets each defined by a multiplet of coordinates in multidimensional space. The first and second holograms are represented by first and second coefficients respectively associated with wavelets. The coding method includes the following steps: for each second coefficient, determining a remainder by a difference between the second coefficient concerned, associated with a first wavelet defined by a given multiplet, and the first coefficient) associated with a second wavelet defined by a multiplet having as its image the multiplet by a transform in the multidimenisonal space; coding the determined remainders. The transform is determined by analysis of variation between the first scene represented by the first digital hologram and the second scene represented by the second digital hologram.

A method of calculating a hologram having an amplitude and a phase component. The method comprises (i) receiving an input image comprising a plurality of data values representing amplitude. The method then comprises (ii) assigning a random phase value to each data value of the plurality of data values to form a complex data set. The method then comprises (iii) performing an inverse Fourier transform of the complex data set. The method then comprises (iv) constraining each complex data value (X1, X2) of the transformed complex data set to one of a plurality of allowable complex data values (GL1-GL8), each comprising an amplitude modulation value and a phase modulation value, to form a hologram, wherein, the phase modulation values (GL1-GL7) of the plurality of allowable complex data values substantially span at least 3π/2 and at least one of the allowable complex data values has an amplitude modulation value of substantially zero (GL8) and a phase modulation value of substantially zero.

There is provided a method of projection using an optical element (502,602) having spatially variant optical power. The method comprises combining Fourier domain data representative of a 2D image with Fourier domain data having a first lensing effect (604a) to produce first holographic data. Light is spatially modulated (504,603a) with the first holographic data to form a first spatially modulated light beam. The first spatially modulated light beam is redirected using the optical element (502,602) by illuminating a first region (607) of the optical element (602) with the first spatially modulated beam. The first lensing effect (604a) compensates for the optical power of the optical element in the first region (607). Advantageous embodiments relate to a head-up display for a vehicle using the vehicle windscreen (502,602) as an optical element to redirect light to the viewer (505,609).

Disclosed are a method and an apparatus for processing phase information. When receiving a phase image including phase information, a processing device performs phase remapping of mapping the phase image to a predetermined range. The predetermined range is a range of a first phase value to a second phase value having a period of 2π, and a difference between the first phase value and the second phase value is 2π.

A hologram display device includes a light generator generating light, a spatial light modulator forming an interference pattern to interfere with the light, and a controller providing interference data to the spatial light modulator to form the interference pattern. The spatial light modulator includes a first area in which pixels are arranged in a first pattern, and a second area in which pixels are arranged in a second pattern. The controller includes a data generator generating first interference data for the first area and second interference data for the second area, a compensator generating first correction data based on the first interference data and second correction data by correcting the second interference data, and an output unit generating the interference data based on the first correction data and the second correction data.

There is provided a holographic projector comprising a hologram engine and a controller. The hologram engine is arranged to provide a hologram comprising a plurality of hologram pixels. Each hologram pixel has a respective hologram pixel value. The controller is arranged to selectively-drive a plurality of light-modulating pixels so as to display the hologram. Displaying the hologram comprises displaying each hologram pixel value on a contiguous group of light-modulating pixels of the plurality of light-modulating pixels such that there is a one-to-many pixel correlation between the hologram and the plurality of light-modulating pixels.